The invention concerns a roller tappet particularly for a high pressure fuel pump or for a valve train of a quality or quantity regulated internal combustion engine, said roller tappet comprising a housing on whose drive side end are arranged two diametrically opposing flats that are pressed in from an outer peripheral surface of the housing, each of said flats comprising a receptacle, a pin carrying a cam roller being mounted in said flats, an inner peripheral surface of the housing, as viewed in a drive distal direction, being penetrated axially below the cam roller by a bridge member, and a driven side end of the bridge member comprising a support for a tappet follower.
A generic roller tappet is disclosed in FIG. 1 of DE 10 2006 028 851 A1. The pin of this roller tappet for the cam roller is fixed by positive and force engagement either through a front-end caulking or through a radial spot or gyratory riveting.
The pre-cited measures necessitate separate machines and lead to an unnecessary increase of manufacturing costs and time. In addition, a quality control of the caulked or riveted connection proves to be relatively complex and destructive. Besides this, it is clear that a person skilled in the art who considers implementing the aforesaid method is restricted in the choice of the material for the pin although the more recent prior art also manifests core hardened and subsequently radial spot riveted pins (s. DE 10 2006 054 404 A1).
Alternatively to the aforesaid measures, U.S. Pat. No. 5,385,124 discloses a snap ring and groove connection for a pin. This necessitates additional work steps for working the groove and mounting the snap ring, the more so because, according to the standard, the surrounding structure of the bore for the pin with groove requires a minimum width and the grooves needed in the surrounding structure as well as in the pin weaken the material of each of these.
Moreover, a centerless grinding of an outer peripheral surface of the housing of the roller tappet according to the pre-cited document DE 10 2006 028 851 A1 proves to be problematic because there is a danger for the housings, which have to be positioned anew for grinding, to tilt out of place.